The Internet workgroup develops the MIP for implementing that a terminal may transmit information via the Internet protocol (IP) link. The MIP provides an IP routing mechanism for the terminal. With the mechanism, the terminal supporting MIP may be connected to any link with a preset terminal identifier. The terminal supporting MIP may change the location without interrupting the information transmission via links or restarting. The following description takes a mobile station (MS) as the terminal for example.
Currently, there are two techniques for the MS to support the MIP. One is called the client mobile Internet protocol (CMIP) technique which integrates the MIP function into the MS. The MIP registering/MIP deregistering procedure of the MS are both initiated by the MS. Another technique is called the proxy mobile Internet protocol (PMIP) technique which sets the MIP function in a proxy mobile node of an access service network (ASN) to which the MS attaches. The MIP registering/MIP deregistering procedure of the MS are both initiated by the proxy mobile node.
No matter the CMIP technique or the PMIP technique is used by the MS to perform the MIP registering/MIP deregistering procedure, there is a need to establish a security association between an entity with the MIP function and a home agent (HA) providing service for the MS. When the MS uses the CMIP technique, the entity with the MIP function is the MS. When the MS uses the PMIP technique, the entity with the MIP function is the proxy mobile node.
When the MS using the CMIP technique performs the MIP registering/MIP deregistering procedure, the MS initiates an MIP registering request/an MIP deregistering request which carries security association information to the HA via an access service network gateway/foreign agent (ASN GW/FA) of the ASN to which the MS attaches. The HA authenticates the security association information carried by the request. If the authentication succeeds, the HA establishes/releases link resource between the HA and the MS. The link passes the ASN GW/FA of the ASN to which the MS attaches. If the authentication fails, the HA performs no operations and returns a request failure response to the MS via the ASN GW/FA of the ASN to which the MS attaches.
When the MS using the PMIP technique performs the MIP registering/MIP deregistering procedure, the proxy mobile node to which the MS attaches initiates the MIP registering request/MIP deregistering request carrying the security association information to the HA via the ASN GW/FA of the ASN. The HA authenticates the security association information carried by the request. If the authentication succeeds, the HA establishes/releases the link resource between the HA and the proxy mobile node. The link passes the ASN GW/FA of the ASN to which the MS attaches. If the authentication fails, the HA performs no operations and returns the request failure response to the proxy mobile node via the ASN GW/FA of the ASN to which the MS attaches.
The MIP deregistering procedure is applied for the MS using the CMIP technique or the PMIP technique and in the normal network exit procedure. The MS performs the MIP deregistering procedure after transmitting the information via the link. However, with regard to the MS which uses the CMIP technique and terminates unconventionally, such as sudden power-off or breaking away from the ASN to which the MS attaches, the MIP deregistering procedure may not be initiated because the MIP deregistering request may not be initiated. Therefore, only when an MIP life cycle set for the MS by the HA decreases to 0, does the HA automatically initiate the MIP deregistering request for the MS and release the link resource between the HA and the MS. If the MIP life cycle set for the MS by the HA is long, the network side still charges for the MS as the link resource between the MS and the HA has not been released although the MS terminates unconventionally. It is unacceptable to the MS.
FIG. 1 is a schematic view illustrating the architecture of the worldwide interoperability for microwave access (WiMAX) network. The MS may perform the MIP technique in the WiMAX network. The WiMAX network includes the MS, the ASN, and a connectivity server network (CSN). The ASN includes a base station (BS) to which the MS attaches, an anchor authenticator/proxy mobile node and an ASN GW/FA. The CSN includes an Authentication Authorization and Accounting (AAA) server and the HA. The thick solid lines in FIG. 1 indicate interfaces defined in the WiMAX. The point line indicates logical interfaces undefined in the WiMAX. The thin solid line indicates standard interfaces in the communication network. The broken line indicates air interfaces defined in the Standard 802.16.
When the MS performs the CMIP technique, the MS establishes the link resource between the MS and the HA via the BS to which the MS attaches and the ASN GW/FA. When the MS performs the PMIP technique, the MS establishes link resource between the MS and the HA via the BS to which the MS attaches, an anchor authenticator/proxy mobile node and the ASN GW/FA.
In the WiMAX network, with regard to the MS which uses the CMIP technique and terminates unconventionally, the MIP deregistering procedure may be performed by using an authentication routeway from the HA to the anchor authenticator/proxy mobile node via the AAA server. The specific procedure of the MIP deregistering is that first, when the BS to which the MS attaches has detected an unconventional termination of the MS, the BS sends a notification message of the unconventional termination carrying an MS identifier of the MS to the anchor authenticator/proxy mobile node. Second, according to the MS identifier of the MS, the anchor authenticator/proxy mobile node which has received a notification message determines the HA providing service for the MS. The HA providing service for the MS corresponding to the link may be identified because a corresponding relationship between the MS identifier of the MS and the link resource has been preserved in the anchor authenticator/proxy mobile node when the MS performs the MIP registration. The anchor authenticator/proxy mobile node sends a remote authentication dial in user service (Radius) message carrying the MS identifier of the MS to the AAA server to which the HA attaches. The HA provides service for the MS. Finally, the AAA server retransfers the Radius message to the HA providing service for the MS. The link resource related to the MS is determined by the HA providing service for the MS according to the MS identifier of the MS. The HA providing service for the MS may get the link resource corresponding to the MS because the corresponding relationship between the MS identifier of the MS and the link resource has been preserved in the HA providing service for the MS when the MS performs the MIP registration. The HA providing service for the MS releases the link resource between the MS and the HA, i.e. the HA releases the link resource between the HA and the MS via the ASN GW/FA and the BS to which the MS attaches, so the MIP deregistering is performed.
In the MIP deregistering procedure in the WiMAX network, there is a need to modify the content of current Radius message which is applied in the charging and authentication for the MS, and modify the software in the AAA server and the HA for the purpose that the AAA server and the HA whose software has been modified may support the modified Radius message, then perform the MIP deregistering procedure according to the modified Radius message. The current Radius message is applied in the charging and authentication for the MS.
In addition, with regard to the MS which uses the PMIP technique and terminates unconventionally in the WiMAX network, the MIP deregistering procedure may be performed by a pre-built security association between the proxy mobile node and the HA. The specific procedure of the MIP deregistering procedure is that first, when the BS to which the MS attaches has detected the unconventional termination of the MS, the BS sends the notification message of the unconventional termination carrying the MS identifier of the MS to the anchor authenticator/proxy mobile node. Second, according to the MS identifier of the MS, the anchor authenticator/proxy mobile node which has received the notification message determines the MS and the HA providing service for the MS, and initiates the MIP deregistering request carrying the security association information of the MS to the HA providing service for the MS via the ASN GW/FA. Finally, the HA providing service for the MS authenticates the security association information carried by the request. If the authentication succeeds, the HA providing service for the MS releases the link resource between the HA and the anchor authenticator/proxy mobile node. The link passes the ASN GW/FA. If the authentication fails, the HA providing service for the MS performs no operations and returns the request failure response to the anchor authenticator/proxy mobile node via the ASN GW/FA.
The MIP deregistering procedure by the security association information in the WiMAX network may perform the MIP deregistering procedure of the MS which uses the PMIP technique and terminates unconventionally. However the MS which uses the CMIP technique and terminates unconventionally may not perform the MIP deregistering by the security association information.
Therefore, a problem to be solved is how to enable the MS using the CMIP technique during the unconventional termination to perform the MIP deregistering, without need of waiting for the end of the life cycle of the MIP set by the MS and modifying the current Radius message.